Muhammad bin Ishaq bin Yasar (may Allah have mercy on him) says: The first apostasy among the Arabs was that of Musaylimah in Yamamah, who was of Banu Hanifah, and of al-Aswad bin Ka'b al-Ansi in Yemen, during the very lifetime of the Prophet (peace and blessings be upon him); and Tulayhah bin Khuwaylid al-Asadi of Banu Asad, who claimed prophethood and used to compose rhymed speech for them all.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قتال أهل البغي / 16727